A number of diseases can lead to severe impairment of normal lung functioning. Among these are: Cystic Fibrosis, Emphysema, and Immotile Celia Syndrome. Cystic Fibrosis is a hereditary disease that leads to the accumulation of large quantities of viscous mucus in the lungs. Emphysema causes impairment of the lung's ability to clear mucus as a result of damage to the celia, the small hair-like vibrating appendages covering the lung wall that loosen and help propel the mucus out of the lung; and damage to the alveoli, the small air sacs covering the lung surface, which are instrumental in coughing mucus out of the lungs. Immotile Celia Syndrome is a hereditary disease in which the normal functioning of the celia is absent or impaired, leading to the accumulation of mucus in the lungs. In all of these diseases, mucus retained in the lungs becomes a natural breeding ground for harmful bacteria that can cause repeated bouts of serious infections, as well as leading to decreased respiratory gas exchange.
In addition to drugs and inhalants, various physical therapies may be applied to assist in expelling mucus from the pulmonary system. In particular, patients may undergo chest percussion by a trained physical therapist to loosen lung mucus, which is followed by postural drainage and coughing to expel the mucus from the lungs. This can be a time consuming and discomforting therapy which meets with only limited success, especially if the patient is in a weakened condition.
More recently, high-frequency chest compression techniques have been employed as a means of eliminating the need for a physical therapist, and to improve effectiveness of mucus clearance from the lungs. Such techniques have been taught by Warwick and Hansen, U.S. Pat. No. 4,838,263; Hansen, U.S. Pat. No. 5,569,170; and Warwick and Hansen, U.S. Pat. No. 6,958,046. High-frequency chest compression, as applied by an inflatable vest, has been shown in clinical trials and in actual use to be efficacious in clearing mucus from the lungs. However, a patient may require 2 to 3 hours of treatment each day to keep the lungs relatively free of mucus.
The present invention addresses the need for a more effective approach to clearing mucus from the pulmonary system that will reduce physical stress to the body, and require less time in the daily regimen of treatment.